/Engine/Source/Runtime/Engine/Classes/Interfaces/NetworkPredictionInterface.h
(Client) After receiving a network update of position, allow some custom smoothing, given the old transform before the correction and new transform from the update.
virtual void SmoothCorrection &40; const FVector & OldLocation, const FQuat & OldRotation, const FVector & NewLocation, const FQuat & NewRotation &41;